The present invention relates to a method for producing pulp molded articles suitable to keep things in such as powders or liquids and to pulp molded hollow containers.
Plastics are used as general materials of packaging containers, for example, those with a lid and bottles, for their excellent molding properties and productivity. However, because plastic containers involve various problems associated with waste disposal, pulp molded containers formed by pulp molding have been attracting attention as substitutes for plastic containers. Pulp molded containers are not only easy to dispose of but economical because they can be manufactured by using regenerated paper.
Pulp molded containers having the above-described characteristics are produced by, for example, immersing a papermaking net shaped in conformity to the shape of a molded article in a pulp slurry, evacuating water contained in the slurry through the papermaking net by means of a vacuum pump, etc. to deposit pulp fiber on the surface of the net, and transferring the net to a drying oven where the pulp fiber is dried to obtain a pulp molded container as disclosed in Japanese Patent Publication No. 51-34002.
In the above method, however, it is difficult to clear the papermaking net of the residual fiber attached thereto. In addition, since the pulp fiber clings to the papermaking net, making it difficult to release and take out the molded article from the net after papermaking and drying, which imposes restrictions on product design.
Japanese Patent Application Laid-Open No. 71900/80 discloses a method for producing a pulp molded article which comprises covering the surface of a mold with a continuous flat porous woven fabric, depositing pulp fiber on the porous woven fabric in conformity to the configuration of the mold, dehydrating and drying the pulp deposited body, and releasing the pulp molded article from the porous woven fabric and the mold.
According to the above method, since the porous woven fabric is merely brought into contact with the mold surface, it is difficult to conform the porous woven fabric to the contour of the mold in case where a product having a depth of 60 mm or more or a product having such a complicated shape as having projections, different levels, etc. is to be molded. Further, the method is costly because the mechanism for transferring the mold and the porous woven fabric used in the above method is complicated and requires large-sized equipment.
Accordingly, an object of the present invention is to provide a method for producing a pulp molded article by which a pulp molded article having a complicated shape with a uniform thickness can be manufactured without requiring large-sized equipment and with ease in removing the molded article from the mold and to provide a pulp molded hollow container.
The present invention has achieved the above object by providing a method for producing a pulp molded article which is characterized by comprising the steps of depositing pulp fiber on the surfaces of a set of splits for papermaking having a plurality of interconnecting holes connecting the outside and the inside to form a pulp deposited body on each split and closing the splits to join the pulp deposited bodies together.